2 Samuel 12:29-31

29So David gathered the rest of the army and went to Rabbah, and he fought against it and captured it.

30David removed the crown from the king’s head, and it was placed on his own head. The crown was made of gold and set with gems, and it weighed seventy-five pounds. David took a vast amount of plunder from the city.

31He also made slaves of the people of Rabbah and forced them to labor with saws, iron picks, and iron axes, and to work in the brick kilns. That is how he dealt with the people of all the Ammonite towns. Then David and all the army returned to Jerusalem.